液体黏滞阻尼器在超高层结构上的抗震抗风效果和经济分析

为了保护地震及大风环境下的高层和超高层建筑,加设液体黏滞阻尼器是目前被工程界广泛认同、发展最为迅速、最为有效的结构振动保护方案。综合介绍国内外安装液体黏滞阻尼器的7座高层建筑,对阻尼器的安置方式、减振结构的抗震(振)效果、相关规范以及经济性进行评述。其中墨西哥Mayor大楼、美国波士顿大楼是世界工程界成功应用耗能减震装置的经典案例,银泰中心、盘古大观是我国首批使用阻尼器进行减振控制的超高层建筑,对这些工程采用的计算分析方法,结构抗震设计进行汇总,并提供相关建议和意见,供设计者参考。近期美国几位学者在一座42层钢筋混凝土结构的概念设计中,提出采用阻尼器替代剪力墙体系进行抗震设计的理念,对这一高层建筑工程的抗震新方向进行介绍,引为参考。     

门式起重机支腿自顶向下的设计方法

通过对门式起重机支腿的功能进行综合分析,应用SolidWorks软件,提出一种支腿的自顶向下(Top-Down)设计方法,并利用开发工具Visual Basic对支腿进行快速变型设计。首先根据门式起重机支腿的功能要求,构建顶层基本骨架模型;然后确定各零部件以及零部件之间的结合方式,进行支腿主模型设计;最后,在主模型完成设计的基础上,利用Visual Basic与Solidworks API对支腿主模型进行参数化变型设计。该设计思路符合工程实际中从概念设计到详细过程的设计思路,显著提高了设计效率,符合缩短现代产品设计周期的客观需求。     

Seismic assessment of RC core‐wall building capable of three plastic hinges with outrigger

In a core‐wall structure with buckling restrained braces (BRB) outrigger, locations of the plastic hinges are influenced by the outrigger action. Therefore, the designer should consider the issue and use suitable details in the plastic hinge area. The essential questions that arise here are the plastic hinge location and the design moment demand used for design of this kind of structure. In this paper, responses of the core‐wall buildings with BRB outrigger designed by using the traditional response spectrum analysis procedure are assessed by implementing the nonlinear time history analysis. The result demonstrates that the plasticity can extend over anywhere within the core‐walls specially, at the base and above or below the outrigger levels. Formation of three plastic hinges in the core‐wall is recognized suitable for the system. To control the plasticity extension in the core‐wall, it is recommended that a new modal combination method be applied to calculate the moment strength of the three plastic hinges over the height. A capacity design concept is used to design other regions of the core‐wall where the plasticity does not extend to. The proposed procedure improves behavior of the system by restricting the plasticity extension to the predefined plastic hinge regions. Copyright © 2016 John Wiley & Sons, Ltd.     

Shaking table test on seismic resonant behavior of core‐outrigger structure

In order to investigate disastrous seismic resonant effect of resonant ground motions on tall building structures, a 1/40 scaled planar test model of a 56‐story core‐outrigger structure was tested on shaking table considering two types of ground motions, that is, non‐resonant and resonant ground motions. The non‐resonant ground motions were chosen from far‐field natural earthquake records, whereas the resonant ground motions were generated through scaling Fourier spectra of the non‐resonant ones in a target period region covering one of the first two natural periods of the test model. The test results showed that (a) with the same small peak ground acceleration of 0.07 g, the test model exhibited significant hysteretic behavior, residual displacement, and even overturning collapse under the resonant ground motions but behaved elastically under the non‐resonant ones; (b) the first‐period resonant ground motion caused extremely large displacements on the upper floors and large moments on the lower stories, whereas the second‐period resonant ground motion resulted in extremely large accelerations on the upper and middle floors; (c) the first‐period resonant ground motion was more probable to trigger overturning collapse of the core‐outrigger system after some exterior columns had reached their axial compression strength, even for those columns on the middle stories.     

旋转惯容阻尼伸臂控制体系减震性能研究

旋转惯容阻尼器(rotation inertia damper,RID)具有质量小、阻尼力大的特点,应用于伸臂结构体系时必须考虑其转动惯量的影响。通过研究RID工作机理,推导了RID伸臂控制体系的振动微分方程,并提出了该体系的地震响应简化算法;考虑RID转动惯量影响,研究了结构各参数与地震响应的关系及其对减震效果的贡献。结果表明：RID伸臂控制体系的地震响应简化算法计算结果合理,与有限元法结果吻合较好;RID的质量参数对伸臂位置及阻尼参数的最优值影响甚微,而且对结构地震响应的影响也可忽略;外柱刚度将显著影响伸臂位置与阻尼器参数的最优值,而且当外柱刚度较大时有利于RID的性能发挥;RID伸臂控制体系具有良好的减震性能,即使在RID质量参数较大的情况下,也能保证其阻尼力在等效力中起主导作用。     

伸臂刚度对加强层设置位置的影响分析

根据伸臂结构的简化模型和伸臂与外框柱的变形协调条件,考虑伸臂的实际刚度,导出伸臂对核心墙的附加力矩,求得结构顶点侧移。对伸臂位置变化引起的侧移变化与内力突变进行了分析,结合工程分析结果对高层建筑加强层设计提出了一些参考意见。     

高层建筑中伸臂桁架的耗能性能研究

伸臂桁架是超高层结构中的关键构件,改善其耗能能力对提升结构的抗震性能具有重要意义.常见的伸臂桁架形式主要有普通支撑型伸臂桁架、屈曲约束支撑型(BRB)伸臂桁架和阻尼型伸臂桁架等.该文从框架-核心筒-伸臂桁架结构体系入手,对普通支撑型、屈曲约束支撑型和阻尼型伸臂桁架的受力性能和耗能性能进行了研究.结果表明,结构采用不同的...     

中国国际丝路中心超高层结构设计与关键技术

吊车横向水平荷载是厂房设计中一项很重要的荷载,其取值的大小对厂房结构的安全和经济合理性都有很大影响。本文通过对14个车间起重量为5～75吨的电动桥式吊车工作时的实测资料进行统计的数理分析,认识到吊车工作时产生的横向水平力有:刹车力、卡轨力和综合力三种,各有其特征,其中起控制作用的是卡轨力。经分析研究,在保证率为95％的情况下,初步提出了这三种力的计算公式。     

消能伸臂体系减震性能的参数变异性影响分析

为研究结构参数变异性对消能伸臂体系减震性能的影响,推导了该体系的有限元振动方程,同时提出地震响应简化分析的“Maxwell型阻尼器计算法”,并结合Gauss-Hermite降维算法分析了确定性激励、随机地震激励作用的参数变异影响情况。结果表明:Gauss-Hermite降维算法既能保证精度又能提高计算效率;确定性激励时,传统伸臂体系与消能伸臂体系的楼层响应标准差随变异系数的增大而增大,但后者的标准差更小;随机激励时,消能伸臂体系仍具有良好的减震性能,且对参数变异敏感性弱,鲁棒性更好。     

NX Nastran在起重机支腿改进设计中的应用

介绍了运用NX Nastran软件对起重机支腿进行有限元分析,在此基础上提出一种新型结构方案,提高了产品使用的可靠性,为产品的改进设计提供了一条新思路。